/****************************************************************************
 *
 * Copyright 2018 Samsung Electronics All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 *
 ****************************************************************************/
/****************************************************************************
 * arch/arm/src/stm32/stm32_exti_gpio.c
 *
 *   Copyright (C) 2009, 2011-2012, 2015 Gregory Nutt. All rights reserved.
 *   Copyright (C) 2011 Uros Platise. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *           Uros Platise <uros.platise@isotel.eu>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <tinyara/config.h>
#include <tinyara/irq.h>
#include <tinyara/arch.h>

#include <stdint.h>
#include <stdbool.h>
#include <errno.h>
#include <debug.h>

#include <arch/irq.h>

#include "up_arch.h"
#include "chip.h"
#include "stm32_gpio.h"
#include "stm32_exti.h"

/****************************************************************************
 * Private Data
 ****************************************************************************/

/* Interrupt handlers attached to each EXTI */

static xcpt_t stm32_exti_callbacks[16];

/****************************************************************************
 * Public Data
 ****************************************************************************/

/****************************************************************************
* Private Functions
****************************************************************************/

/****************************************************************************
 * Interrupt Service Routines - Dispatchers
 ****************************************************************************/

static int stm32_exti0_isr(int irq, void *context)
{
	int ret = OK;

	/* Clear the pending interrupt */

	putreg32(0x0001, STM32_EXTI_PR);

	/* And dispatch the interrupt to the handler */

	if (stm32_exti_callbacks[0]) {
		ret = stm32_exti_callbacks[0](irq, context, NULL);
	}

	return ret;
}

static int stm32_exti1_isr(int irq, void *context)
{
	int ret = OK;

	/* Clear the pending interrupt */

	putreg32(0x0002, STM32_EXTI_PR);

	/* And dispatch the interrupt to the handler */

	if (stm32_exti_callbacks[1]) {
		ret = stm32_exti_callbacks[1](irq, context, NULL);
	}

	return ret;
}

static int stm32_exti2_isr(int irq, void *context)
{
	int ret = OK;

	/* Clear the pending interrupt */

	putreg32(0x0004, STM32_EXTI_PR);

	/* And dispatch the interrupt to the handler */

	if (stm32_exti_callbacks[2]) {
		ret = stm32_exti_callbacks[2](irq, context, NULL);
	}

	return ret;
}

static int stm32_exti3_isr(int irq, void *context)
{
	int ret = OK;

	/* Clear the pending interrupt */

	putreg32(0x0008, STM32_EXTI_PR);

	/* And dispatch the interrupt to the handler */

	if (stm32_exti_callbacks[3]) {
		ret = stm32_exti_callbacks[3](irq, context, NULL);
	}

	return ret;
}

static int stm32_exti4_isr(int irq, void *context)
{
	int ret = OK;

	/* Clear the pending interrupt */

	putreg32(0x0010, STM32_EXTI_PR);

	/* And dispatch the interrupt to the handler */

	if (stm32_exti_callbacks[4]) {
		ret = stm32_exti_callbacks[4](irq, context, NULL);
	}

	return ret;
}

static int stm32_exti_multiisr(int irq, void *context, int first, int last)
{
	uint32_t pr;
	int pin;
	int ret = OK;

	/* Examine the state of each pin in the group */

	pr = getreg32(STM32_EXTI_PR);

	/* And dispatch the interrupt to the handler */

	for (pin = first; pin <= last; pin++) {
		/* Is an interrupt pending on this pin? */

		uint32_t mask = (1 << pin);
		if ((pr & mask) != 0) {
			/* Clear the pending interrupt */

			putreg32(mask, STM32_EXTI_PR);

			/* And dispatch the interrupt to the handler */

			if (stm32_exti_callbacks[pin]) {
				int tmp = stm32_exti_callbacks[pin](irq, context, NULL);
				if (tmp != OK) {
					ret = tmp;
				}
			}
		}
	}

	return ret;
}

static int stm32_exti95_isr(int irq, void *context)
{
	return stm32_exti_multiisr(irq, context, 5, 9);
}

static int stm32_exti1510_isr(int irq, void *context)
{
	return stm32_exti_multiisr(irq, context, 10, 15);
}

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: stm32_gpiosetevent
 *
 * Description:
 *   Sets/clears GPIO based event and interrupt triggers.
 *
 * Parameters:
 *  - pinset: gpio pin configuration
 *  - rising/falling edge: enables
 *  - event:  generate event when set
 *  - func:   when non-NULL, generate interrupt
 *
 * Returns:
 *  The previous value of the interrupt handler function pointer.  This value may,
 *  for example, be used to restore the previous handler when multiple handlers are
 *  used.
 *
 ****************************************************************************/

xcpt_t stm32_gpiosetevent(uint32_t pinset, bool risingedge, bool fallingedge, bool event, xcpt_t func)
{
	uint32_t pin = pinset & GPIO_PIN_MASK;
	uint32_t exti = STM32_EXTI_BIT(pin);
	int irq;
	xcpt_t handler;
	xcpt_t oldhandler = NULL;
	int nshared;
	xcpt_t *shared_cbs;
	int i;

	/* Select the interrupt handler for this EXTI pin */

	if (pin < 5) {
		irq = pin + STM32_IRQ_EXTI0;
		nshared = 1;
		shared_cbs = &stm32_exti_callbacks[pin];
		switch (pin) {
		case 0:
			handler = stm32_exti0_isr;
			break;

		case 1:
			handler = stm32_exti1_isr;
			break;

		case 2:
			handler = stm32_exti2_isr;
			break;

		case 3:
			handler = stm32_exti3_isr;
			break;

		default:
			handler = stm32_exti4_isr;
			break;
		}
	} else if (pin < 10) {
		irq = STM32_IRQ_EXTI95;
		handler = stm32_exti95_isr;
		shared_cbs = &stm32_exti_callbacks[5];
		nshared = 5;
	} else {
		irq = STM32_IRQ_EXTI1510;
		handler = stm32_exti1510_isr;
		shared_cbs = &stm32_exti_callbacks[10];
		nshared = 6;
	}

	/* Get the previous GPIO IRQ handler; Save the new IRQ handler. */

	oldhandler = stm32_exti_callbacks[pin];
	stm32_exti_callbacks[pin] = func;

	/* Install external interrupt handlers */

	if (func) {
		irq_attach(irq, handler, NULL);
		up_enable_irq(irq);
	} else {
		/* Only disable IRQ if shared handler does not have any active
		 * callbacks.
		 */

		for (i = 0; i < nshared; i++) {
			if (shared_cbs[i] != NULL) {
				break;
			}
		}

		if (i == nshared) {
			up_disable_irq(irq);
		}
	}

	/* Configure GPIO, enable EXTI line enabled if event or interrupt is
	 * enabled.
	 */

	if (event || func) {
		pinset |= GPIO_EXTI;
	}

	stm32_configgpio(pinset);

	/* Configure rising/falling edges */

	modifyreg32(STM32_EXTI_RTSR, risingedge ? 0 : exti, risingedge ? exti : 0);
	modifyreg32(STM32_EXTI_FTSR, fallingedge ? 0 : exti, fallingedge ? exti : 0);

	/* Enable Events and Interrupts */

	modifyreg32(STM32_EXTI_EMR, event ? 0 : exti, event ? exti : 0);
	modifyreg32(STM32_EXTI_IMR, func ? 0 : exti, func ? exti : 0);

	/* Return the old IRQ handler */

	return oldhandler;
}
